Dual Self-Trapped Exciton and Rare-Earth Emissions from Sb3 + /Pr3 + -Activated Metal Halide toward Plant Cultivation Lighting, Dynamic Multilevel Anti-Counterfeiting, and High-CRI WLEDs

Abstract Solid-state lighting technologies for protected horticulture and data security demand luminescent materials whose emission characteristics can be precisely engineered. Here, a novel lead-free double perovskite Cs2NaLuCl6:Sb3+,Pr3+ was synthesized via a hydrothermal route to supply the blue and red photons essential for plant photosynthesis. Incorporating Sb3+ (ns2 configuration) into the host lattice generates broadband blue self-trapped exciton (STE) emission, while codoping with Pr3+ establishes an efficient energy-transfer pathway from STEs to the Pr3+ 3P0 state, promoting the 3P0 → 3F2 transition at 653 nm to produce intense red light, thereby achieving blue-red dual-band emission within a single-component matrix. The as-fabricated LED exhibits an internal quantum efficiency of 59.09% and a spectral coincidence of 87.91% with the chlorophyll b absorption profile. Furthermore, leveraging its excitation-wavelength-dependent photoluminescence, a multilevel dynamic anticounterfeiting system employing excitation selectivity and long-pass optical filtering was demonstrated. A high-quality white LED was also constructed, achieving a color rendering index of 91.2, a correlated color temperature of 3602 K, and CIE coordinates of (0.3948, 0.3736). This work provides a high-performance phosphor for horticultural lighting, anticounterfeiting, and display applications.